Signal flare for floating mines

ABSTRACT

This invention relates to the cutting of the lines by which explosive mines are anchored in bodies of water, and more particularly to signal flares that are carried by the cutting tools until the lines are cut.

lUmaied Ses @eene [w1 Temple el al. [45] Sept. 4, E973 [54] STGNAL FLARE FOR FLOATNG MINES [75] Inventors: Robert Temple, Swissvale; Ernest E. [56] References Cited Temple, Murrysville; `loseph L. UNITED STATES PATENTS Giebel, SwiSSvale, all 0f Pa- 2,423,859 7/1947 Kamer 102/90 ux 2,430,698 ll/l947 Allen [73] Assgnee sebyppphans Company 2,689,963 9/1954 Jackson 9/8.3

[22] Filed: Mar. 8, i961 Primary Examiner-Samuel Feinberg [21] Appl No 94 179 Attorney-Brown, Critchlow, Flick & Peckham [57] ABSTRACT [52] U'S' Cl 9/8'3 R 114/221 Al(l)(2)/23{.138 This invention relates to thecutting of the lines by [51] im C! H6311 21/5'2 which explosive mines are anchored in bodies of water, I 58] Fie'ld /221 221 l. and more particularly to signal flares that are carried by 102/7, 8,10, 1l, l2, 13, 14, 35, 37.8, 90; 89/l.01, l A; 9/8, 8.3, 9

the cutting tools until the lines are cut.

PTENTEU SEP 4 M5 SHEE 10F@ ROBERT .QA/57 E. TEMP/.E JOSEPH L. 615561. BY

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PATENTE() SEP 4 ma SHEEW N 4 INVENTORS.

TEMPLE ERNEST E TEMPLE JOSEPH L GIEBEL SIGNAL FLARE FOR FLOATING MINES In the copending patent applications, Ser. Nos. 591,368 and 640,754 filed .lune 14, 1956 and Feb. 18, 1957, respectively, several different signal flares that can be used with mine anchor-line cutters of the explosively actuated type are shown. When a cutter encounters a mine anchor-line, the cutter is fired and lthe'fline is cut. Simultaneously, a flare is released v'from the cutter and floats to the surface. As it is released, a chemical carried by the flare is exposed to the surrounding water. The wet chemical is one that generates a'gas'that will burn the moment the chemical reaches `the 'air above the water. The purpose of the flare is to provide a floating torch that will show that a mine has been cut loose and has risen to the surface nearby. f course, the flare has its principal utility when minesweeping is done at night. At such times there isalways the ydanger of a floating mine, which has been cut loose, being lost or being run into by another ship in the mine sweeping fleet, due to the fact that darkness hides the mine. Although the flares shown in my copending application are satisfactory in general, the need for faster rising flares increases as mines are planted at greater depths. For cutting at great depths, the flares disclosed in said patent applications are not entirely suitable because it takes too long for them to reach the surface of the water.

It is among the objects of this invention to provide signal flares which will rise to the surface of a body `of water very quickly from extreme depths.

The invention is illustrated in the accompanying drawings, in which FIG. 1 is a fragmentary bottom view of the cutting end of a mine anchor-line c utter provided with Aour improved flare;

FIG. 2` is an enlarged fragmentary front view of the cutter;

FIG. 3 is a cross section taken on the line III-III of FIG. 1;

FIG. 4 is an enlarged longitudinal section through a flare and its container;

FIG. 5 is a side view of the flare;

FIGS. 6 and 7 are views similar to FIGS. l and 2, 'respectively, of a modification;

FIG. 8 is a cross section taken on the line VIII-VIII of FIG. 6;

FIG. 9 is an enlarged side view of the modified flare container in its holder; and

FIG. 10 is a further enlarged longitudinal section through the flare and its container.

Referring to FIGS. l and 2 of the drawings, a stabilizing fin 1 has'its longitudinal axis extending in the direction in which the cutter is pulled through the water by a sweep line 2 extending backward and laterally from a mine sweeper (not shown) in a well-known manner. The front edge of the fin is inclined to its longitudinal axis the same degree as the sweep line. This front edge is provided at its opposite ends with integral ears 3 that hook over the sweep line. Bolts 4, extending through the fin and each ear, hold the fin on the sweep line.

Rigidly mounted on the front portion of the fm is the metal frame 6 of the cutting tool. The longitudinal axis of the frame extends across the tin, and the frame is set back from the front corner of the fm so that only a small amount of the frame extends across the inclined front edge of the fin. The front side of this outwardly projecting portion of the frame is provided with a recess l7 that extends lengthwise of the frame. The frame also is provided with a longitudinal bore extending inwardly from the inner end of the recess, and this bore normally contains a cutting chisel 8 that is held in retracted position by shear pin 9 extending through it and the surrounding frame.

The end of the frame beside the recess is provided with a slot 1l for receiving a tongue 12 on one end of a guide member 13. The tongue and frame are provided with aligned transverse passages, through which a shear -pin 14 extends. The guide member 13 extends across the end of the recess 7 to form an anvil l5, and then the guide turns and extends along the front side of the recess'toward the chisel. At a point spaced from the chisel, the guide is inclined forward away from the frame -to form a finger 16 that will intercept a minevanchor line and direct it into the cutting notch formed by recess 7 between the guide and frame.

When a mine-anchor line 18, across which the sweep line and fin have been dragged, is caught in the cutting notch, it is cut by the chisel which is driven against it -by the force of an explosion from a cartridge (not shown) removably mounted in the frame at the inner orrear end of the chisel. During cutting, the mine line is backed up by the front and back walls of the cutting notch, and by the anvil l5 in the path of the chisel. To Vexplode the cartridge, a firing mechanism is mounted in the -inner ye'iid of the frame. This mechanism forms no part 'of this invention and is not shown, but it can be seen in U.S. Pat. No. 2,422,506. It includes a plunger 19 slidably mounted in a guiding slot 20 extending lengthwise 'of the back side of the frame. Connected to the rear end of the plunger is a rod 2l that is slidably mounted in a bore through a block 22 rigidly mounted 'in slot 20 behind the cutting notch. The plunger is urged toward theinner end 'of the frame by a coil spring 23 encircling the rod and compressed between the plunger and block 22. The plunger normally is held in retracted position, with the spring compressed, by means of a trip pin 24 of small diameter extending through guide member 13, across the cutting notch, through the frame and into a transverse opening 25 in the plunger rod.

Whena mine anchor-line 18 enters the cutting notch, it engages 'the trip pin 24, the front end of which is held in fixed position by engagement of its head with guide member 13. As the anchor line bends the pin toward anvil 15, the rear end ofthe pin is pulled out of the plunger rod, thereby releasing the plunger. The released plunger actuates the firing mechanism, as described in detail in said patent, and the cartridge is detonated. The force of the explosion builds up until it is sufficient to cause the cutting chisel to shear off pin 9. The chisel then shoots forward, and in cutting the anchor line it also shears off the portion of trip pin 24 in `the cutting notch. Shear pin 14, which connects guide member 13 to the frame, is strong enough to hold the anvil in4 place until the chisel has severed the anchor line. The impact of the chisel against the anvil then causes the tongue l2 of guide member 13 to shear off pin ld and slide out of frame slot lll. Release and loss of the guide member in this manner is justified because, otherwise, the next mine anchor-line might catch in the cutting notch, where it-would not be cut.

As soon as a mine anchor-line is cut, the mine that is thereby released rises to the surface of the water and floats there until detonated in some suitable manner. It is a feature of this invention that the presence of the mine floating on the water is.clearly and immediately indicated at night when the mine otherwise might not be seen. Accordingly, a buoyant flare is carried by the cutter in such a manner that it will be released when the cutter is fired and will rise to the surface with the mine, where it will immediately burst into flame and serve as a beacon.

The flare shown in FIGS. 3, 4 and 5 is formed from two major parts; a float 30 and a chemcial receptacle 3l having a closed inner end and an open outer end. The receptacle is filled with chemical 32, which is held in place by a screen 33 secured across the open end of the receptable. The chemical produces a flame when the flare reaches the surface of the water. This chemical is calcium phosphide, which may have calcium carbide mixed with it. When such a chemical becomes wet, it immediately generates a gas. The calcium phosphide gas will burst into flame in the presence of oxygen, but the calcium carbide gas must be ignited by the first gas. The float has a screw 34 embedded in it and projecting from its inner end into a threaded oepning 3S in the closed end of the receptacle to connect the two parts together.

The flaot is elongated and it flares out or increases in diameter away from the chemical receptacle. The outer end of the float is substantially hemispherical. The float is thus streamlined to offer the least possible resistance to its travel straight up through water without wobbling. Preferably, the float is made of a rigid sponge plastic 36 that will not be crushed by the pressure of the water around it. To prevent the water from forcing itself into the pores of the float and thereby increasing its weight, the float is covered by a thin latex sheath 37, the open end of which is tied around the adjoining end of the chemical receptacle in a groove 38. A flare constructed in this manner has been found to rise through water much more rapidly than the'ones shown-in the patent applications mentioned above.

In order to keep the chemical in the flare dry until it is to be used, the flare is sealed in a container, which -includes a tubular body 40 that is closed at its opposite ends by caps 41 and 42 encircled by sealing gaskets 43 as shown in FIG. 4. Since the flare is to be released from the container by breaking the container, the latter may be made from glass, but preferably from a brittle plastic. To insure that the chemical receptacle will always be located at the correct end of the container relative to the anchor-line cutter, the container is tapered and the internal diameter of its smaller end is less than the diameter of the larger end of the float. The chemical receptacle is centered in the container by a pair of laterally spaced fillers 44, preferably a shock absorbing plastic, molded to tit part way around the receptacle and the smaller end portion of the float. These fillers also support the flare laterally so that screw 34 will not be bent by the force of the impact that releases the flare from the cutter. The two fillers may be integrally connected at their outer ends.

In order to attach the flare container to the anvil l of the anchor-line cutter, a holder is provided that is secured to the cutter by a metal strap 46. As shown in FIGS. l, 2 and 3, the holder is formed from two separable parts, each of which is of general semicylindrical shape. One part 47 has an end wall 48 at one end, and the other part 49 has an end wall 50 at the opposite end, these two end walls each fitting into the adjoining end of the other part and preferably spacing the two parts a short distance apart. Holder part 47 is secured to a metal bracket 5,2 that straddles the anvil of the cutter to position the holder on the end of the cutter. The rear end of the bracket is always placed against shoulder 53 of the cutter frame and, as holder part 47 is secured to the bracket in a position that has previously been determined to be most effective for releasing the flare, the holder will always bear the correct relation to the cutter. Strap 46 holds the two parts of the holder together and holds the bracket against the outer face of the anvil. Preferably, and especially when the anvil is made of a relatively soft metal, a hardened cutting block 54 is held against the inner surface of the anvil by the strap. The strap and block are in the path of chisel 8.

It will be seen that when the strap is cut by the chisel, the flare holder will be released from the cutter and the two parts of the holder will separate. Preferably, strap 46 is made of spring metal so that it will spring open when cut. The tremendous shock of the chisel striking cutting block 54 is supposed to shatter the flare container and fillers 44. To avoid any possibility of that not happening, the ends of the container and holder are provided with interengaging pins and openings. Preferably, the pinsSS and 56 project from the centers of the container caps 4l and 42 and into holes 57 and 58, respectively, in the end walls of the holder. To make certain that the flare will be located in correct position relative to the anvil, one of the pins and the hole that receives it are made larger than the other pin and hole so that the container will fit only one way in the holder. When the strap is severed and the two parts of the holder fly away from each other, they exert a twisting action on the container through its end pins, which helps to break up the container so that the flare will be sure to escape from it immediately.

Shattering of the container also is promoted by providing it with integral, external ribs 59 extending lengthwise of it. The ribs increase in thickness toward the smaller end of the container, as shown in FIG. 4. The ribs seem to provide lines of strain in the container that help it to break apart.

As will be seen in FIG. 4, front cap 4l of the flare container is recessed to receive the rounded end of the float, but the side of the recess is provided with circumferentially spaced grooves 60 to permit the water pressure on the opposite sides of the cap to equalize when the container is broken, so that the cap will be sure to separate from the float. Without such grooves or their equivalent, it has been found that the cap sometimes adheres to the float and slows its upward progress through the water.

ln'the modification shown in FIGS. 6 to l0, the flare 65 may be the same as the one just described, but its container and holder are different. The container body 66 preferably is molded from a brittle plastic and has an open end and a closed end. The open end is closed by a cap 67 inserted in it to seal the container. The inside of the container is shaped to tit against the chemical receptacle 68 and the float 69. The outside may be tapered away from the cap and provided with integral ribs 70 extending lengthwise of the container.

The holder 72 that receives the container has an open side. One end of the holder, preferably the front end, has an end wall 73 provided with a central opening 74 (FIG. 7), in which is inserted a pin 7S projecting from the closed end of the container body. The pin is held in the opening by means of a retaining pin 77 extending across the opposite end of the container. The retaining pin, such as a cotter pin, extends through holes in opposite sides of the holder and preferably through a slot 78 in the container cap, whereby the retaining pin locks the container in the holder. The closed side of the holder is secured to a bracket 79 that straddles the outer face of the anvil of the cutting tool. The bracket is held in place by a strap 81, preferably spring metal, extending across the open side of the holder, along opposite sides of the bracket and around the anvil. Usually a hardened cutting block 82 is inserted between the strap and the innerface of the anvil.

When the cutter is tired, the chisel 8 first severs a mine anchor-line 18 in the cutter recess 7 and then cuts the strap. At the same moment the shock of the impact of the chisel against the cutting block or anvil shatters the flare container and thereby releases the flare from it and the holder. The are immediately rights itself` and starts rising to the surface of the water. It does this without wobbling, which would slow its ascent.

According tothe provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

l. A signal flare device for use with an explosively actauted mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, holding means containing the container, ends of said means and container being provided with an interengaging central pin and opening, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said tiring, whereby to release said flare.

2. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, holding means for the container provided with openings receiving said pins, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said tiring, whereby to release said flare.

3. A signal flare device according to claim 2, in which said container comrpises a tubular body and caps sealed in the ends of the body, said pins projecting from the centers of the caps.

4t. A signal flare device according to claim 3, in which the inside of said tubular body is tapered toward one end, and one of said pins has a smaller diameter than the other.

5. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, a multi-part separable holder for the container having opposite ends provided with openings snugly receiving said pins, a hardened metal cutting block, and a strap for holding said holderparts together and attaching the holderand block to opposite sides of an anchor-line cutterr anvil, said strap being severable against said block whenthe cutter is fired under water, ans said container being shatterable by the shock of said tiring to release it from said holder and freethe flare.

6. A signal flare device for use withan explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible contaienr for the flare having opposite ends provided with outwardly projecting pins, a separable holder for the container having opposite ends provided with openings receiving-said pins, and means for holding the holder together and attaching it to an anchor-line cutter, said attaching means being fonned for releasing said holder when the cutter is tired under water, and said container being shatterable by the shock of said firing to release said flare.

7. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, a hollow holder for the container formed in two parts each having an end wall provided with an opening snugly receiving one of said pins, and a strap for holding said parts together and attaching the holder to an anchor-line line cutter, said strap being severable by the firing of the cutter under water to release said holder parts from each other, and said container being shatterable by the shock of said firing to release it from said holder and to free the flare.

8. A signal flare device according to claim 7, including a bracket secured to the side of one of said holder parts and formed for straddling the front end of an anchor-line cutter to position the holder on the cutter.

9. A signal flare unit comprising a flare having a chemical housing with one vend rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular shatterable body containing the flare, and caps sealing the ends of said body.

10. A signal flare unit comprising a flare having a chemical housing rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular frangible body containing the flare, said body tapering internally toward the housing end of the flare, the internal diameter of the smaller end of the body being less than the diameter of the largest part of said float, caps sealing the ends of said body, and axially aligned pins projecting outwardly from the center of the caps, one of the pins having a larger diameter than the other.

ll. A signal flare unit comprising a flare having a chemical housing with one end rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular shatterable body containing the flare, and caps sealing the ends of said body, the inner surface of the cap at the float end of the tube being recessed and fitting over said rounded end of the float, and said inner surface having a groove extending across the end of the float.

l2. A signal flare unit comprising a flare having a chemcial housing with one end rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, and a hollow shatterable container for the flare tapering toward the housing end ofl the flare, the outside of the container having integral'solid ribs extending lengthwise thereof.

13. A signal flare unit comprising a flare having a chemical housing rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, and a hollow frangible container for the flare tapering internally toward the housing end of the flare, and laterally seperable fillers in the container occupying the space between the container and said chemical housing and the smaller end portion of the float.

14. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, holding means containing the container and having only one end wall, said wall and the adjacent end'of the container being provided with an interengaging central pin and opening, a retaining pin extending across the opposite end of the container and through the adjacent sides of said holding means, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said firing, whereby to release said flare.

l5. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, a holder for the container having an open side, ends of the holder and container being provided with an interengaging central pin and opening, and a strap for attaching said holder to an anchor-line cutter anvil, the strap extending across the open side of the holder and being severable when the cutter is fired under water, and said container being shatterable by the shock of said tiring to free the flare. 

1. A signal flare device for use with an explosively actauted mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, holding means containing the container, ends of said means and container being provided with an interengaging central pin and opening, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said firing, whereby to release said flare.
 2. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, holding means for the container provided with openings receiving said pins, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said firing, whereby to release said flare.
 3. A signal flare device according to claim 2, in which said container comrpises a tubular body and caps sealed in the ends of the body, said pins projecting from the centers of the caps.
 4. A signal flare device according to claim 3, in which the inside of said tubular body is tapered toward one end, and one of said pins has a smaller diameter than the other.
 5. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, a multi-part separable holder for the container having opposite ends provided with openings snugly receiving said pins, a hardened metal cutting block, and a strap for holding said holder parts together and attaching the holder and block to opposite sides of an anchor-line cutter anvil, said strap being severable against said block when the cutter is fired under water, ans said container being shatterable by the shock of said firing to release it from said holder and free the flare.
 6. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible contaienr for the flare having opposite ends provided with outwardly projecting pins, a separable holder for the container having opposite ends provided with openings receiving said pins, and means for holding the holder together and attaching it to an anchor-line cutter, said attaching means being formed for releasing said holder when the cutter is fired under water, and said container being shatterable by the shock of said firing to release said flare.
 7. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare having opposite ends provided with outwardly projecting pins, a hollow holder for the container formed in two parts each having an end wall provided with an opening snugly receiving one of said pins, and a strap for holding said parts together and attaching the holder to an anchor-line line cutter, said strap being severable by the firing of the cutter under water to release said holder parts from each other, and said container being shatterable by the shock of said firing to release it from said holder and to free the flare.
 8. A signal flare device according to claim 7, including a bracket secured to the side of one of said holder parts and formed for straddling the front end of an anchor-line cutter to position the holder on the cutter.
 9. A signal flare unit comprising a flare having a chemical housing with one end rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular shatterable body containing the flare, and caps sealing the ends of said body.
 10. A signal flare unit comprising a flare having a chemical housing rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular frangible body containing the flare, said body tapering internally toward the housing end of the flare, the internal diameter of the smaller end of the body being less than the diameter of the largest part of said float, caps sealing the ends of said body, and axially aligned pins projecting outwardly from the center of the caps, one of the pins having a larger diameter than the other.
 11. A signal flare unit comprising a flare having a chemical housing with one end rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, a tubular shatterable body containing the flare, and caps sealing the ends of said body, the inner surface of the cap at the float end of the tube being recessed and fitting over said rounded end of the float, and said inner surface having a groove extending across the end of the float.
 12. A signal flare unit comprising a flare having a chemcial housing with one end rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, and a hollow shatterable container for the flare tapering toward the housing end of the flare, the outside of the container having integral solid ribs extending lengthwise thereof.
 13. A signal flare unit comprising a flare having a chemical housing rigidly connected to one end of an elongated float that flares towards its opposite end and has a rounded outer end, and a hollow frangible container for the flare tapering internally toward the housing end of the flare, and laterally seperable fillers in the container occupying the space between the container and said chemical housing and the smaller end portion of the float.
 14. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, holding means containing the container and having only one end wall, said wall and the adjacent end of the container being provided with an interengaging central pin and opening, a retaining pin extending across the opposite end of the container and through the adjacent sides of said holding means, and means for attaching the holding means to an anchor-line cutter, said attaching means being formed for releasing said holding means when the cutter is fired under water, and said container being shatterable and releasable from said holding means by the shock of said firing, whereby to release said flare.
 15. A signal flare device for use with an explosively actuated mine anchor-line cutter, comprising a buoyant flare, a sealed frangible container for the flare, a holder for the container having an open side, ends of the holder and container being provided with an interengaging central pin and opening, and a strap for attaching said holder to an anchor-line cutter anvil, the strap extending across the open side of the holder and being severable when the cutter is fired under water, and said container being shatterable by the shock of said firing to free the flare. 